Is your smoke alarm over 10 years old?

We are urging residents living in homes built between 1992 and 2008 to have their hard-wired smoke alarms replaced.

Research into their longevity has concluded that hard-wired as well as battery-operated devices should be replaced every 10 years, or sooner if they do not respond properly when tested.

The manufacturing industry also recommends that smoke alarm detector heads should be replaced every decade.

Countless Cheshire homes are being protected by smoke alarms that are more than 10 years old, with misguided faith in hard-wired alarms being a particular concern.

Smoke alarms save lives - they detect fires in their early stages and give a loud audible warning and they help you to save your home and the lives of your family. But simply having smoke alarms in your home is not enough - you have to be sure that they are working.

People are generally aware that battery-operated smoke alarms need to be replaced every 10 years, but they seem to think that mains-wired alarms will last forever. Yet they use the same technology and so have the same shelf life.

In 1992 the Building Regulations were amended requiring every new build to have mains-wired interconnected smoke alarms installed. So all homes built in Cheshire between 1992 and 2008 have smoke alarms that need replacing, unless the homeowners have already replaced them over the past decade.

Some of these homes have smoke alarms that are now nearly 30 years old and desperately need replacing. With contaminants such as dust, insects, grease and nicotine, over time the smoke alarm chamber is susceptible to becoming excessively sensitive or insensitive. This may lead to either an increase in nuisance false alarms, or to it eventually becoming unable to detect smoke.

Similarly, as smoke alarms get older faults are more likely to occur. Corrosion of electrical circuitry and disconnected power supply is another possible problem with hard-wired alarms.

Smoke alarms should be tested regularly, but the tests may not be reliable with old alarms. You may get a bleep when you press the test button but this may give a false impression of fully functioning alarm.

The only way to be sure that a smoke alarm over 10 years old will work properly when you need it to is to have its smoke detector head replacing. This needs to be done by a qualified electrician with mains-wired alarms, but the cost is a small price to pay for knowing that the alarm will alert you should a potentially life-threatening fire start in your home.

Research

The majority of research into smoke detector longevity emanates from America. The US National Fire Protection Association (NFPA) has issued NFPA Standard 72: National Fire Alarm and Signalling Code (2010 edition), which states: “Replace all smoke alarms, including those that use 10-year batteries and hard-wired alarms, when they are 10 years old or sooner if they do not respond properly when tested.”

American fire safety websites, along with those in the UK, Canada, New Zealand and Australia, tend to recommend the replacement of domestic smoke alarms, whether battery operated or mains wired, when they fail to respond to tests and are 10 years old.

The Minnesota Department of Public Safety cites a nationwide study undertaken by the US Consumer Product Safety Commission (CPSC), which states that 97 per cent of smoke alarms should still be functioning after one year, if supplied with power. After 10 years it is 73 per cent and after 20 years it is 54 per cent. The study also indicated that 60 per cent of smoke alarm failures were due to flat or removed batteries or a disconnected power supply.

An NFPA report cites a study undertaken by Canada’s Ontario Mortgage and Housing Corporation which concluded that three per cent of smoke alarms will fail within a year and nearly all alarms will have failed after 30 years. It also concluded that replacement after 10 years, with roughly a 30 per cent probability of failure, is an appropriate balance between safety and cost.

The Australian standard for smoke alarms (AS 3786) specifies an effective life of 10 years.